Scientist from Stockholm University questioned the efficiency of a lie detector that had been bought by the British Governement, among others. The company threatned with a libel process and the article was removed from the publisher's on-line publication.

Published data on the frequency of the voice fundamental (F0) in speech show its range of variation, often expressed in terms of two standard deviations (SD) of the F0-distribution, to be approximately the same for men and women if expressed in semitones, but the observed SD varies substantially between different investigations. Most of the differences can be attributed to the following factors: SD is increased in tone languages and it varies with the type of discourse. The more ‘lively’ the type of discourse, the larger it is. The dependence of SD on the type of discourse tends to be mom pronounced in the speech of women than of men. Based on an analysis of various production data A is shown that speakers normally achieve an increased SD by increasing the excursions of F0 from a ‘base-value’ that lies about 1.5 SD below their mean F0. This is relevant to applications in speech technology as well as to general theories of speech communication such as the ‘modulation theory’ in which the base-value of F0 is seen as a carrier frequency.